In this work, we show how we can improve the image resolution capabilities of a Phase Conjugating (PC) lens as well as the angular resolution of Luneburg lens antennas by employing signal processing techniques such as the Correlation Method (CM), the Minimum Residual Power Search Method (MRPSM), the sparse reconstruction method, and the Singular-Value-Decomposition (SVD)based basis matrix metho...

We present a review of several types of microwave antennas made of metamaterials, including the resonant electrically small antennas, metamaterial-substrate patch antennas, metamaterial flat-lens antennas, and Luneburg lens antennas. In particular, we propose a new type of conformal antennas using anisotropic zero-index metamaterials, which have high gains and low sidelobes. Numerical simulatio...

Rotman lens is a true-time-delay beam forming network with parallel plate structure. Owing to its frequencyindependency and wide-band operation, it has gained vast applications as feeding element of linear array antennas. However, the lens suffers from high intrinsic power loss and the problem worsens in microstrip structures by their inevitable dielectric loss. On the other hand, waveguides ex...

According to General Relativity, the large scale structures of the Universe can influence a light beam remotely by their gravitational fields, resulting in a gradual systematic ‘expansion’ of the beam which reflects the curvature of space. We show that if such an effect is present, any random speed v in the masses will cause the frequency ωo of the arriving extragalactic light to deviate slight...

With a conventional lens sharpness of the image is always limited by the wavelength of light. An unconventional alternative to a lens, a slab of negative refractive index material, has the power to focus all Fourier components of a 2D image, even those that do not propagate in a radiative manner. Such "superlenses" can be realized in the microwave band with current technology. Our simulations s...

Quasi-optical (QO) active circuits have originally received interest for power generation by large-scale power combining of solid-state devices at microwave and millimeter-wave frequencies. Here, we present an overview of QO components developed with functionality in mind, with an emphasis on bidirectional amplifier arrays for transmit/receive (T/R) front ends. We discuss possible advantages of...

Refraction at a smooth interface is accompanied by momentum transfer normal to the interface. We show that corrugating an initially smooth, totally reflecting, non-metallic interface provides a momentum kick parallel to the surface, which can be used to refract light negatively or positively. This new mechanism of negative refraction is demonstrated by visible light and microwave experiments on...

Modern electrical and communication technologies benefit from classical electrodynamics and electric circuits, both of which are based on the Maxwell’s equations. Using the property of metric invariance in Maxwell’s Equations, transformation optics has been proposed and achieves a rapid progress in the past decade. Transformation optics is a method for the conceptual design of complex electroma...